Shot-firing apparatus



March 5, 1929. c, Q JOHNSON 1,704,131

SHOT FIRING APIARATUS Filed Aug. 22. 1927 2 Sheets-Sheet l In] Inventor 627/73 6. :70Zf/00/7 14 imrizg March 5, 1929. c. c. JOHNSON SHOT FIRING APPARATUS Filed Aug. 22', 192'? 2 Sheets-Sheet Inventor gar/fa 6. Moi/mm? Attornqy Patented Mar. 5, 1929.

UNITED STATES CARLTON CLINTON JOHNSON, O1! OSWEGO, KANSAS.

SHOT-FIRING arrana'rus.

Application filed August 22, 1827. Serial No. 214,709.

This invention relates to machines for firing explosive charges or shots in mine workings or the like, and comprises an electrically controlled circuit closing apparatus adapted to travel upon a track arranged in the mine and embodying a trip actuating mechanism arranged upon engagement therewith to close the electric circuit to which the explosive charge or shot is connected whereby to cause the firing thereof.

An object of the invention is to provide an apparatus of this character having means for operatively controlling the same arranged at a remote part of the mine, or at the mouth thereof by means of which the movement of the circuit closing apparatus may be controlled and adapted during its movement to engage any desired number of separate trip elements arranged on the track adjacent the 0 room or working in the mine within which the charge or shot is to be fired, said circuit closing device being adapted for actuation upon contact thereof with each of the trip mechanisms.

A further object of the invention is to provide indicating means at the point of control of the apparatus adapted for actuation'upon the firing'of each of the shots whereby to enable the operator to determine whether or not the firing of the shot has actually been completed.

A still further object is to provide an apparatus of this character of simple and practical construction, which is safe from injury or damage during the firing of the shot, efiicient and reliable in performance, which provides means for exploding or firing any desired number of shots within a mine working in successive order without requiring the presence of an attendant at any point in close proximity to the position at which the shots are fired and which is otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the special construction and combination of the various parts constituting the invention, reference being had to the accompanying drawings forming a part hereof, wherein Figure 1 1s a side elevational View of the carriage constituting the circuit making and breaking apparatus.

Figure 2 1s a similar view taken from the opposite side thereof.

Figure 3 is an end view, and,

F igure 4 is a diagrammatic view showing the electric circuit for controlling the same.

Referring now to the drawings in detail, a track is indicated at 5 arranged in suspended position from the roof of the main or sub entries extending within a mine working or the like by any suitable supporting means, the upper and lower edges of the track being provlded with strips of conductive material indicated at 6 and insulated from each other by the body of the track. A carriage is adapted to travel alon the track, comprising a frame indicated at 3 having a supportin member 8 extending thereabove, upon which is rotatably mounted a flanged pulley wheel 9 adapted to travel upon the upper edge of the track. A gear wheel 10 is also carried on the pulley shaft 11 engaged by a worm 12 on a shaft 13 extending from an electric motor 14 attached to the frame and to which electric wires 15 and 16 are attached for the operation of the motor whereby to drive the pulley 9 through the worm and gear.

The conductor strip 6 arranged on the opposite sides of the track are charged with electric current from a suitable source, as by means of a battery indicated at 17 having a connection with said conductor strips through the wires 18 and in which is interposed a twopole double throw switch 19 adapted through the operation thereof to reverse the flow of current through said conductor strips whereby to reverse the operation of the motor 14 enabling the carriage to be driven in a forward or rearward direction as desired.

The current from the conductor strip is transmitted to the motor by means of the contact of the upper strip by the pulley 9 to which the wire 16 is connected for leading to the motor, the circuit being completed through the lower strip of the track by means of a similar pulley 20 attached to the carriage and engaging the underside of the track and to which the wires 15 extending to the motor are attached. In this manner, the carriage may be moved in any desired direction upon the track through the control of the switch 19.

The opposite end of the carriage is also provided with a flange pulley wheel 21 likewise engaging the underside of the track and supported at one end of a bellcrank 22 pivotally supported to the carriage by a pivot pin 23 with the opposite end of the bellcrank tensionally retained for engaging the pulley with the track by a spring 24 extending between the bellcrank and the carriage. The carriage is thus balanced at each end to smoothly traveling upon the track.

A commutator 25 is rotatably mounted on the upper end of an arm 26, said arm belng pivotally mounted on the carriage by a piyot pin 27 the upper end of the arm on which the commutator is carried being normally retained in upwardly extending position by means of a spring 28 attached to the lower end of the arm and connected to a stationary part of the carriage. The lower end of the arm 26 has an upwardly extending pro ection 29 formed thereon adapted through the.

downward movement of the upper end or the arm to close a switch 30, comprising a pair of contact members indicated respectively at 31 and 32, one of said contact members having an electric wire 33 connected therewith and extendin to a relatively large induction coil or an A. transformer indicated at 34. The induction coil or transformer has its terminals connected in parallel by wires 35 and 36 with the wires 15 and 16 supplying current to the motor 14. The opposite contact member 32 of the switch is connected by a wire 37 and arranged in this circuit with the wire 15 extending from the pulley 20.

The wire 33 extending from the contact member 31 of the switch is operatively connected with the primary circuit of the induction coil or transformer, which through its action is adapted to deliver a high-voltage current through the wire 28 which extends through the commutator 25.

A trip 39 is adapted to extend from one side of the track, in the nature of a projection, arranged to be engaged by the commutator 25 as the carriage travels along the track. The trip is insulated from both of the conductor strips 6 of the track and carries a contact plate adapted to be engaged by the commutator and connected through a wire 40 to the charge or shots 41, the circuit for which is completed through a Wire 42 connected with the upper conductor strip 6 of the track.

By throwing the switch 19 so as to cause the carriage to move in a direction toward the trip 39, the engagement of the contact plates on the trip with the commutator operates to complete the circuit with the induction coil or transformer whereby to fire the shot. It is to be understood that the engagement of the commutator with the trip will not interfere with the movement of the carriage and the same may continue to travel along the track for the firing of additional shot in the same manner as described above, which may be arranged through the mine working. An ammeter indicated at 43 may be interposed in the electric circuit adjacent the switch 19 adapted to register any increase of current used and 1s accordingl actuated when any of the shots are fire thereby serving as a check for the attendant to show whether or not a particular shot or charge has been exploded.

It is apparent that the trip 39 arranged for contact with the commutator may be placed at any desired position upon the track and remote from the room or workin in the mine at which the shot is placed so t at the carriage carrying the circuit closing apparatus may not be in close proximity to the working at the time the shot is fired, thus preventing any danger of injury to the apparatus. Likewise, the control switch may be mounted in a position remote from the mine, as for instance, above the mine entrance, so that the attendant need not be exposed to any danger during the firin of the shot.

urthermore, any desire number of shots may be arranged for firing in successive order during the traveling oi the carriage, a check for the firing of each shot bein provided for by means of the ammeter an upon the completion of the firing of the shot the current for operating the carriage may be reversed so as to return the same to any desired position along the track.

The track 5 may also be provided with one or more additional conductors indicated at 44 in Figure 4: for use in case a three phase A. C. is desired to beemployed in the operation of the device or to register its operation.

The carriage may further be equipped with a suitable recording device operatively connected with the ammeter or other electrically operated device, adapted to indicate upon the recorder, the discharge of the shots as they are fired, whereby to establish a positive record of the same.

Should the operator desire to control the speed of the carriage, a rheostat may be interposed in the circuit in series with the ammeter.

Due to the change in the type of electric caps or squibs employed in shot firing, it may be desired to dispense with the use of the step-up transformer, in which event the circuit is closed through contacts placed along the track forming a shunt circuit from the conductors 6 direct with the shot.

It is obvious that the invention is susceptible of various changes and modifications, without departing from the spirit or scope of the invention as hereinafter claimed, and sacrificing any of its advantages, and I accordingly claim all such forms of the device to which I am entitled.

I claim 1. In'an apparatus of the class described, a track, electric conductor strips arranged thereon, a carriage adapted for movement along the track, carriage drive means carried thereby and adapted for operation through the conductor strips on the track a shot firing circuit, a circuit closer therefor, carried by the carriage, and actuating means for the closer arranged in the path of movement of the carriage and operable for circuit closing movement upon engagement with said closer.

2. In a device of the class described,a track, conductor strips arranged thereon, a carriage mounted for movement on the track, carriage drive means carried thereby and adapted for operation through the conductor strips, a shot firing circuit, and a circuit closer having actuating means arranged in the path of movement of the carriage whereby to close the circuit upon the passage of the carriage over the ground.

3. In a device of the class described, a track, conductor strips thereon, a carriage mounted for movement on the track, carriage drive means arranged thereon and adapted for operation through the conductor strips, a shot firing circuit, a circuit closer therefor having actuating means arranged in the path of movement of the carriage and operable through the movement of the carriage over the track and control means for the carriage remotely arranged therefrom.

4. In a device of the class described, a track, conductor strips thereon, a carriage mounted for movement on the track, having an electrically operated motor arranged thereon for driving the carriage, means for energizing the motor through the conductor strip, a circuit closer carried by the carriage, trip means adapted to actuate the same, a shot firing circuit arranged for energization upon the actuation of said circuit closer and control means for the carriage remotely arranged therefrom.

5. In a device of the class described, a track, conductor strips thereon, a carriage mounted for movement on the track, carria e drive means arranged thereon and adapted for operation through the conductor strip, means for supplying a source of current to said conductor strips, a circuit closer carried by the carriage, trip means adapted to actuate the same, a shot firing circuit connected with the source of current, and normally in circuit open position and adapted to be closed upon the actuation of said circuit closer, and control means for the carriage remotely arranged therefrom.

6. In a device of the class described, a track, conductor strips thereon, a carriage mounted for movement on the track, carriage drive means arranged thereon and adapted for actuation through the conductor strips, means for supplying a source of current to said conductor strips, a circuit closer carried by the carriage, a shot firing circuit connected with the source of current and normally in circuit open position, a shunt circuit connected with the conductor strips, a step-up transformer interposed therein, and contact means on the carriage adapted through the actuation thereof to operate said circuit closer and connect said shot firing circuit and said shunt circuit in circuit closed position with the source of current.

7 In a device of the class described, a track, conductor strips thereon, a carriage mounted for movement on the track, carriage drive means arranged thereon and adapted for op,- erat-ion through the conductor strips, means for supplying a source of current to said con ductor strips, a circuit closer carried by the carriage, a shot firing circuit connected with the source of current and normally in circuit open position, a shunt circuit connected with the conductor strips, a step-up transformer interposed therein, and contact means on the carriage and adapted through the actuation thereof to operate said circuit closer and simultaneously close said shot firing circuit with said shunt circuit and connecting the same.

8. In combination, a track, conductor strips arranged thereon, a carriage mounted for movement on the track, a motor on the carriage operatively connected with the strips, drive means for the carriage connected with the motor, a source of current for the conductor strips, a switch interposed between the motor and the source of current adapted to reverse the operation thereof, a shunt circuit connected with the motor, a step-up transformer interposed therein, a circuit breaker therefor, a trip arranged on the track, a breaker arm on the carriage engageable thereby for closing the shunt circuit, a shot firing circuit connected with the source of current and normally arranged in open position, and acommutator carried on saidbreaker arm and insulated therefrom and connected with the primary circuit of said transformer and adapted to close said shot firing circuit upon the actuation of the arm for closing the shunt circuit.

In testimony whereof I afiix my signature.

CARLTON CLINTON JOHNSON. 

